Hundreds of cars lined the main roads of Yemen’s capital after the rebels who control the city ordered fuel stations to close on Wednesday, accusing merchants of taking advantage of a Saudi blockade to hike prices. A Saudi-led military coalition tightened its blockade in Yemen this week after a ballistic missile fired by Houthi rebels was intercepted near the Saudi capital. Aid groups say the measures will exacerbate an already severe humanitarian crisis in the impoverished, war-torn country.